1. Field of the Invention
The present invention relates to an electric vehicle and, more particularly, to a battery disconnection unit for an electric vehicle.
2. Description of the Related Art
An electrical driving system of an electric vehicle comprises a charger 10 for rectifying an external commercial Alternating Current (abbreviated as AC hereinafter), converting it into constant Direct Current (abbreviated as DC hereinafter) electric power, and providing the same, an AC motor 40 for driving a driving shaft of a wheel of the electric vehicle, a battery 20 for charging the constant DC power from the charger 1 and supplying DC driving power, an inverter 30 for converting the DC driving power from the battery 20 into AC power that can drive the AC motor 40 and providing the same, a battery disconnection unit 50, and a heater 60 for regulating an ambient temperature of the battery 20.
The battery disconnection unit 50 is a switching circuit unit which may be switched to an electric power supplying position or to an electric power breaking position. The battery disconnection unit 50 may be switched to a position at which DC power is supplied from the charger 10 and a position at which DC power is cut off (or interrupted) between the charger 10 and the battery 20, and may be switched to a position at which DC driving power from the battery 20 or to a position at which the DC driving power is cut off between the battery 20 and the inverter 30. The battery disconnection unit 50 is a terminal portion for an input and output, which comprises a first input terminal T1 for the DC input from the charger 10, a first output terminal T2 for supplying the DC power from the charger 10 to the battery 20, a second input terminal T3 for receiving the DC driving power from the battery 20, and a second output terminal T4 for supplying the DC driving power from the battery 20 to the inverter 30.
The battery disconnection unit according to the related art will now be described. In a high voltage relay performing a power switching function, the capacity of the high voltage relay connected to the charger 10 is as small as, for example, 10 amperes (A), and the capacity of the high voltage relay connected to the inverter 30 is relatively high, which is as high as 100 amperes. In the related art, connection lines of the small capacity high voltage relay and the large capacity high voltage relay are configured as a harness such as a bus bar and/or a wire. Thus, the related art has problems in that the weight of the battery disconnection unit increases, the assembling of the battery disconnection unit are not east, and reliability of the battery disconnection unit deteriorates. In addition, the use of a semiconductor switch is required to control turning on and off the heater for regulating the temperature around the battery, causing a problem in that the bus bar and/or the wire is not suitable as a wiring for the semiconductor switch.